Hi, I got a pair of these for my fluval 403 second hand and I do not know
how they uncouple from each other - can somebody help me out?
Here's a picture of what I am talking about:
http://www.petmeister.com/item966.htm
but mine was not in packaging, so I didn't get instructions.

Thanks!
Jennifer

Nevermind. It was stuck, so I was doing it correctly and didn't realize it.
For those who wondered how it worked, you turn the middle coupler against
one of the valves, not the valves against each other. And it is pretty easy
to do.
Laters,
Jen